This invention relates to an injectable composition of physiologically compatible and appropriately sized particles carried in a lubricative, biologically compatible fluid or gel. The composition is formulated to be delivered into the body to a tissue site through a small-bore instrument to strengthen, bulk-up and otherwise augment the tissue site and surrounding area.
The percutaneous injection of substances into tissues to augment, support, or reconfigure anatomic structure has been the subject of significant research and product development and is well known in the art. See, for example, U.S. Pat. Nos. 4,803,075 and 5,204,382 to Wallace et al and U.S. Pat. No. 5,258,028 to Ersek et al. Procedures have been described in the medical literature for correction of dermatological, otolaryngological problems and for treatment of ufological disorders, e.g., Walker et al., "Injectable Bioglass as a Potential Substitute for Injectable Polytetrafluoroethylene," J. Urol., 148:645-7, 1992 and the references cited therein.
Urinary incontinence and vesicourethral reflux are urological disorders that have responded to treatments with augumentive materials. U.S. Pat. Nos. 5,007,940; 5,158,573; and 5,116,387 to Berg disclose biocompatible compositions comprising discrete, polymeric and silicone rubber bodies injectable into urethral tissue for the purpose of treatment of urinary incontinence by tissue bulking. The most serious adverse effect that may occur from therapies of this type relates to the migration of the solid materials from the original site of placement and into repository sites in various body organs. An important factor in assuring nonmigration is the administration of properly sized particles. If the particle is too small, it is likely to enter the microvasculature system and travel until it reaches a site of greater constriction. Target organs for reposition include the lungs, liver, spleen, brain, kidney, and lymph nodes.
The primary focus of this invention has been directed toward the development of biocompatible, nonmigratory particles that are effectively delivered to the desired tissue site in a lubricative, biocompatible fluid or gel carrier. The preferred carrier shall not cause any deleterious effects at or near the site of particle delivery and will be removed from the site by normal biological or biochemical processes such as excretion or metabolic breakdown.